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View Full Version : alternatives to GWS motors??


Eggvoel
09-18-2005, 02:38 PM
Currently flying Estarter and Formosa with GWS 350 motors, 2c1500 Lipo's and mostly 9070 props. Seems like I have cooked 2 relatively new motors with only a small amount of time on them, yet I have had others that I got lots of flights out of. 1 cooked while flying with a 1047 prop on D gearing and this morning another on 9070 prop with B gearing. The 1047 is recommend by GWS for High Thrust with the D gearing and for High Speed with the C gearing which also cooked a motor.
Should I not be running the 9070 with B gearing and switch to the 8060 or 9047 for high thrust?
Are there better motors (brushed) available at a decent price? Want to go brushless eventually, but funding is scarce right now and I have 4 2c1500 lipo batteries I would like to keep using. To keep both planes flying brushless would require 2 new brushless motors and ESC's and to really gain much I would have to go for 3c lipos and then a new charger as mine only does 2c. thanks. larry

Matt Kirsch
09-19-2005, 04:18 PM
That's the nature of can motors, unfortunately. They're mass produced with very little quality control, and we push them way beyond what they were originally designed to do. Lifespan will be unpredictable. You may get one that burns up in seconds, and another that absolutely refuses to die no matter how much you pound on it...

For the most part, these motors last around 50-100 flights, and low-time "duds" are fairly rare.

Motors with designations like Speed 300, "370", EPS350, etc. are all the same make and model of motor, made by the same company in the same factory with the same quality control problems. Unless you go brushless, there really isn't much hope for improvement.

Eggvoel
09-19-2005, 05:18 PM
Thanks Matt. I thought I have seen other can motors at about twice the price of GWS motors. Are they still one in the same or are there other manufacturers with better quality control?

Twmaster
09-20-2005, 02:21 AM
As Matt pointed out just about all of the can motors come from the same factories and are mostly identical. For example the speed 280 motor in a GWS EPS100 power set is the same exact motor sold by Graupner with a higher price tag.

The two big manufacturers are Johnson and Mabuchi (Spelling?)

unloco2
09-20-2005, 05:01 AM
I have used can brushed motors since the '80s. I like them, I have not had the problems a lot of people have, in fact, I'm still using some from that era. Maybe I'm lucky. The bottom line is cost, not neccesarily performance. I can buy several "can" motors for the price of one brushless, I can buy several speed controls for the price of one brushless controller. The can motors provide all the flying efficiency and life I need or want. My problem is not burning out motors, it's crashing airplanes. I would prefer to burn out motors rather than crash planes. Is there a solution to that?

Sky Sharkster
09-20-2005, 11:46 AM
To Eggvoel, the can motors have a short life but your situation is unusual. Have you been breaking the motors in? An underwater break-in will nearly double the useful life and produce more efficiency throughout. The brushes need to be shaped to the semi-curve (arc) and the dust produced by the shaping, if not removed will clog up the movement and restrict cooling.
The only other cause I can think of would be in-flight overheating, but with 2C Lipos and the correct gear/prop combo this is unlikely. If you would like a short description of the underwater break-in process drop me a PM and I'll send it to you. Good Luck! Sky Sharkster

Unbalanced prop
09-20-2005, 03:31 PM
Back when I flew GWS brushed motors, as long as I kept the 350 under 9 amps I got about what Matt said, 50 - 100 flights. If I remeber right, a 10 x 4.7 on D or C gearing should be fine (6.5 to 8.5 amps), but a 9 x 7 on B gearing may be pulling too much at WOT.

As Sky Sharkster said you may want to try water break-in which seemed to help my motors run better and last longer. Here is a link to how to do the break-in.

http://www.rcgroups.com/forums/showt...water+breakin+

Doug

Eggvoel
09-20-2005, 05:11 PM
Thanks again all. I had read about the water break-in, but haven't done it. It just seemed strange, but I'll try it next time. But, I have been doing a run-in of easy throttle with the plane tied down on the bench for about 10-12 minutes and varying the throttle. I probably put on 50-75 flights running the B gear and 9070 prop wide open on my Estarter and did a couple of crashed that broke the gear box, hence the new motors with gear boxes and they just aren't lasting. I am running the same gear on the Formosa, but can throttle back with it some cause it gets too fast for my capabilites at times.
I'll do the water break-in on the next batch of motors. Thanks. Larry

HoboDog
09-30-2005, 03:16 PM
The link to the water break in procedure doesn't work.
I think you just put the motor in a glass of water and run it until the water gets cloudy. Am I close?

Twmaster
09-30-2005, 03:20 PM
The link to the water break in procedure doesn't work.
I think you just put the motor in a glass of water and run it until the water gets cloudy. Am I close?

Pretty much. I use two D cell batteries to run it while in the water. One thing you want to avoid is too much voltage thereby causing the brushes to arc against the commutator. Arcing bad.

Also note this break in procedure should only be used on sealed 'can' type motors and should -never- be used on modified type motors with replacable brushes as the brushes are too soft and they will get destroyed if you water them.

Unbalanced prop
09-30-2005, 04:19 PM
lets try this link again

http://www.rcgroups.com/forums/showthread.php?t=201081&highlight=water+breakin+

See if it works now.

Doug

HoboDog
09-30-2005, 04:28 PM
That worked. Thanks.

Duster52
10-07-2005, 11:00 AM
I have used can brushed motors since the '80s. I like them, I have not had the problems a lot of people have, in fact, I'm still using some from that era. Maybe I'm lucky. The bottom line is cost, not neccesarily performance. I can buy several "can" motors for the price of one brushless, I can buy several speed controls for the price of one brushless controller. The can motors provide all the flying efficiency and life I need or want. My problem is not burning out motors, it's crashing airplanes. I would prefer to burn out motors rather than crash planes. Is there a solution to that?

I pay very little more for my brushless ESC's than brushed ones. Some of my brushless motors cost $19.00, $40.00 in combo of motor and esc. The other motors I use cost $49.00 with $39.00 esc. They "never" burn out, unless you overload them. If you do overload them they can be easily rewound. I have done it. If you have the power train set up right, they run "forever". And, they have twice the power or run twice as long with the same batteries. It all depends on what you are used to or want.

Eggvoel
10-07-2005, 05:27 PM
I think I discoverd my problem with the burnt out motors. I posted it in another question as it wasn't quite related to this site about alternatives. I needed some weight to balance the CG and put the clay over the motor stick mount and over the top half of the motor excluding the vent ports on the motor. Dumb thing, but I didn't think about it at the time. Probably was causing the overheating and burning up the motors. I usually try to fly 2 or 3 batteries in a row so it never had a chance to cool off.
My Formosa came with the B gearing and a 9070 and 8060 props. I rechecked my manual and that is what it states also for props, but maybe they should have put the C gearing motor instead of the B. Does anyone know if the C gearing is what is supposed to be in there.
Anyway, believe my clay is the cause of the problem. Have some new motors ordered and will see what happens. Also have 904.7 props coming too. Thanks all. Larry

Eggvoel
10-07-2005, 05:30 PM
[quote=Duster52]I pay very little more for my brushless ESC's than brushed ones. Some of my brushless motors cost $19.00, $40.00 in combo of motor and esc. The other motors I use cost $49.00 with $39.00 esc. They "never" burn out, unless you overload them. If you do overload them they can be easily rewound. I have done it. If you have the power train set up right, they run "forever". And, they have twice the power or run twice as long with the same batteries. It all depends on what you are used to or want.[/quote What is your source for these products? Christmas is coming, hope to upgrade then. Sort of on a budget (wrong hobby). Larry

Twmaster
10-07-2005, 05:38 PM
I wonder why GWS included that 9070 prop with your Formosa. I'm looking at the back of the paper card my newest EPS-350C came on and the chart lists the following props for the B gear set:

Speed: 8040, 8043, 9050
Thrust: 8060, 9047

The 9070 has an X indicating not to use it with that gear set and is only recommended as a speed prop on a C or D gear.

Duster52
10-07-2005, 05:42 PM
eggvoel, I got my stuff from Balsa Products. www.balsapr.com (http://www.balsapr.com) There is another site where you can get the BP-21 and ESC combo for about $40. I will try to get it for you. My Motor Max 400F outrunners are from the above site. If I come up with better prices (there are some out there) I will put them here.

Eggvoel
10-07-2005, 07:59 PM
MY manual with the Formosa states 9070 & 8060 prop included. I suspect they just put the wrong motor in the box by mistake and I didn't know any better so I bought more 9070's and another B gear motor for my Estarter.
I've been keeping an eye on the Balspar site, waiting for Christmas. Larry